Hi on some new new build houses I plan to first fix the up stairs radiators in 15mm copper coming up though the floor at the pipe centers for the radiator. i,e rad. length add 45mm per side and the correct distance from the finish wall. However I am debating how to feed the downstairs radiators, this pipe work is usual feed behind the dot and dab plaster. What do people find is the best way of doing this. Thanks for any advice.